Problems with tree-view UI in mobile devices: make the items too big and you have to scroll both vertically and horizontally; make the items too small and you can't select one without accidentally selecting another. Which is the worse of the two evils?
–
Michael LaiSep 19 '13 at 3:00

4 Answers
4

The NestView method for representing a text hierarchy (specifically xml) came up as an answer on a programmers.stackexchange question. This is quite 'out there', but it does save a fair amount of horizontal space, compared to either a tree-view or indented text. It also has the benefit of having a larger 'touch area' than a tree-view, it could possibly also suit more general usage than just hierarchical text structures:

Accordions work if you have flat hierarchies (e.g. one sub level). They keep the user in context and you don't have to remember the other category names since you stay in the screen. The handler for open/collapse the category shouldn't be a small button, but the whole list item instead.

Lists are pretty ease to use and fits perfectly if you have to use multiple sublevels. The following items you should provide for smooth content discovery within subs:
- header with title of the current category
- shortcut which takes you to the top level in the hierarchy
- backup which takes you one level up

From an interaction pov, the main challenge is that browsing trees requires a lot of scrolling up and down to re-find items. Also from an information architecture point of view it might be not the most efficient system to organize information. User has to know in which category the object-to-find is hiding. At least there should be a category specific search. To increase flexibility and improve findability I would also combine it with a tagging system.

I like lists in a mobile context, but I'm having a hard time designing a way to SELECT an item in a tree structure. The problem is: when the user taps on an item, how to differentiate if he wants to select it or to navigate to its subitems? Any examples of this?
–
Eric MarcosMar 26 at 10:14